Occupation: Co-chair, Bill & Melinda Gates Foundation
Best-known for: Co-founding Microsoft, dropping out of college to start a tech company before it was cool
The Seattle-born technologist and philanthropist dropped out of Harvard in 1976, after starting Microsoft with longtime friend Paul Allen in 1975. Microsoft (MSFT) was a runaway success. The company remains the world's largest software provider, and made Bill Gates -- who is worth over $75 billion -- the wealthiest man on Earth. Gates served as Microsoft's CEO through 2008.
In 2000, Bill and his wife Melinda founded the philanthropic Bill & Melinda Gates foundation. Since 2014, the billionaire has devoted most of his time to running the foundation, which focuses on ending poverty and increasing access to healthcare in developing countries and supporting education initiatives in the United States.
Gates stayed on as Microsoft's chairman until 2014, when he took on the more modest role of tech adviser. He remains on Microsoft's board.
Related: Melinda Gates is doubling down on this issue
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